Improvement in oils for lubricating from petroleum



UNITED STATES PATENT OFFICE,

JOHN K. TRUAX, OF PITTSBURG, PENNSYLVANIA.

IMPROVEMENT IN OILS FOR LUBRICATING FROM PETROLEUM.

Specification forming part of Letters Patent No. 137,155, dated March 25, 1873.

To all whom it may concern:

Be it known that 1, JOHN K. TRUAX, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Lubricating-Oil; and I do hereby declare the following to be a full,-clear, and exact description thereof.

In the distillation of the tar or residuum from a previous distillation of petroleum there comes over through the condenser, at the end of the distillation, a substance, generally yellow in color, but turning darkish, and becoming of a greenish brown on exposure to air and light. Its gravity is from 20 Baume down, as the still is nearer off. It is fluid or semi-fluid at 100 Fahrenheit, and becomes harder as the temperature is lowered. It has generally been regarded as of little value, and is known by the name of gum or wax by tar stillmen.

My invention consists in the production of a lubricating oil by treating this residuary wax or product with undistilled petroleum, in the manner hereinafter described.

I take a sufficient quantity of this gum or wax, generally ten per cent, but more or less, as the oil I mix it with is lighter or heavier, or as the compound to be produced is to be of greater or less gravity. If the compound is to be heavier, I add more, and vice versa. By the aid of heat I dissolve this gum or wax, in a still or other suitable vessel, in undistilled petroleum, preferably the natural petroleums of 32 Baum, or thereabout. I then distill off from this mixture such a portion of the light oil as will leave the residue in the still of the desired body and gravity. After oooli'n g it is drawn off, and is ready for use.

The natural petroleum above spoken of may first have the light oil removed, or may be heated and have the gum or wax subsequently mixed with it.

The composition thus produced is of a heav ier gravity than the petroleum used, has more body and greater density, and will not harden Witnesses:

W. N. PAXTON, THOS. B. KERR. 

